PREVENTION OF DISEASES AND ACCIDENTS. 



27 



Were the working miners carefully instructed 

 in. the nature and composition of the atmos 

 phere, and its chymical properties, and particu 

 larly in the nature and composition of the dif 

 ferent gases, were such instructions illustrated 

 by a judicious selection of chymical experi 

 ments, and were the proper practical hints and 

 precautions deduced and clearly exhibited, there 

 cannot be the least doubt that it would be at 

 tended with numerous beneficial results. When 

 a person is ignorant of the noxious principles 

 that may be secretly operating within the sphere 

 of his labours, he will frequently rush heed 

 lessly within the limits of danger ; whereas, a 

 man who is thoroughly acquainted with all the 

 variety of causes which may possibly be in ac 

 tion around him, will proceed in every step with 

 judgment and caution, and, where danger is 

 apparent, will hasten his retreat to a place of 

 safety. 



The injuries which are produced by the stroke 

 of lightning form another class of accidents which 

 are frequently owing to ignorance. It is still to 

 b.e regretted, that, notwithstanding the disco 

 veries of modern philosophy, respecting the 

 electric fluid and the laws of its operation, no 

 hunderguard has yet been invented, which, in 

 all situations, whether in the house, in the 

 street, in the open field, in a carriage, or on 

 horseback, shall serve as a complete protection 

 from the ravages of lightning. Till some con 

 trivance of this kind be effected, it is probable 

 that the human race will still be occasionally 

 subjected to accidents from electrical storms. 

 Such accidents are more numerous and fatal, 

 even in our temperate climate, than is generally 



with it, and even work by its light in the midst of 

 those explosive mixtures which have so often 

 proved fatal when entered with a common lamp or 

 a candle. It transmits its light, and is fed with air, 

 through a cylinder of copper wire-gauze. The aper 

 tures in the gauze are about one-twentieth or one- 

 twenty-fifth of an inch square, and the thickness 

 ox the wire from one-fortieth to one-sixtieth of an 

 inch diameter. The parts of the lamp are : l. The 

 brass cistern which contains the oil. 2. The rim in 

 which the wire-gauze cover is fixed, and which is 

 fastened to the cistern by a moveable screw. 3. An 

 aperture for supplying oil, fitted with a screw or 

 cork, and a central aperture for the wick. 4. The 

 wire-gauze cylinder, which consists of at least 625 

 apertures to the square inch. 5. The second top, 

 three-fourths of an inch above the first, surmounted 

 by a brass or copper plate, to which the ring of sus 

 pension is fixed. 6. Four or six thick Vertical 

 wires, joining the cistern below with the top plate, 

 and serving asprotectin pillars round the cage. 



When the wire-gauze &quot;safety lamp is lighted and 

 mtroduoed into an atmosphere gradually mixed 

 with fire-damp, the first effect of the fire-damp is to 

 increase the length and size of the flame. When 

 the inflammable gas forms one-twelfth of the vo 

 lume of the air, the cylinder becomes filled with a 

 feeble blue flame, but the flame of the wick appears 

 burning brightly within the blue flame, and the light 

 of the wick increases, till the fire damp increases co 

 one-fifth, when it is lost in the flame of the fire 

 damp, which fills the cylinder with a pretty strong 

 ligtU. As long as any explosive mixture of gas ex 

 ists in contact I ith the lamp, so long will it give its 



imagined. From an induction of a variety of 

 facts of this kind, as stated in the public papers 

 and other periodical works, in the year 1811, 

 the author ascertained that more than twenty 

 persons were killed by lightning, or at the rate 

 of a thousand persons every fifty years, during 

 the summer months of that year, within the 

 limits of our island ; besides the violent shocks 

 experienced by others, which did not immedi 

 ately prove fatal, and the damage occasioned to 



light, and when it is extinguished, which happens 

 when the foul air constitutes one-third of the volume 

 of the atmosphere, the air is no longer proper for 

 respiration, for though animal life will continue 

 where flame is extinguished, yet it is always with 

 suffering. 



DAVY S SAFETY LAMP. 



The following are the principal parts of the safety 

 lamp : F is the lamp throwing up a brilliant flame. 

 C is the reservoir, supplied with oil by the tube 31. 

 E E is a frame of thick wire to protect the wire- 

 gauze, A A A A, which has a double top G H. The 

 frame has a ring P attached to it for the convenience 

 of carrying it. The wire-gauze is well fastened to 

 the rim B. 



Notwithstanding the utility of this invention, such 

 is the carelessness and apathy of the working mi 

 ners, that they either neglect to use their safety 

 lamps, or to attend to the means requisite to keep 

 them in order, which carelessness and apathy are 

 the effects of that gross ignorance into which so 

 many of them are sunk. Hence \ve find, that sel 

 dom a year passes in which we do not hear of de 

 structive explosions happening in our coal mines, 

 particularly in England. 



